Address Greptile review:
- customContext.files scope was **/*.py only, so Query Report SQL in .js/.sql/report .json
files didn't get the guide attached as context (the global instructions still applied).
Widen to .py/.js/.sql/report **/*.json.
- The guide's HAVING-alias rule said "with no GROUP BY"; PostgreSQL rejects a SELECT-alias in
HAVING regardless of GROUP BY. Reworded to match (repeat the expression, or move a
non-aggregate predicate to WHERE).
The PostgreSQL server-test job is label-gated, so until it is required the Greptile
PR-review bot is the always-on guard against cross-engine breaks. Extend
.greptile/config.json with `instructions` (and a `customContext` reference to a new
guide) so every review flags new/changed queries that would error on PostgreSQL or
silently diverge from MariaDB, under the prime rule that MariaDB output must not change.
- .github/POSTGRES_COMPATIBILITY.md — the catalogue the bot (and contributors) follow:
hard breaks (loose GROUP BY, MySQL-only funcs, UPDATE..JOIN, HAVING-on-alias,
DISTINCT+ORDER BY, single-quoted alias, varchar bitwise OR, capital identifiers,
set_value(Check,bool)), silent divergences (text case-sensitivity, name-lookup case,
empty-string↔NULL, NULL ordering, ORDER BY..LIMIT 1 tiebreakers, integer division,
distinct-drops-ORDER-BY-on-PG + casefold sorting, function-rewrite parity, UnixTimestamp
TZ), the GROUP BY row-count trap (Max()-wrap vs add-to-GROUP-BY; FD-by-source-table),
the InFailedSqlTransaction/savepoint rule, and the false positives NOT to flag
(.like→ILIKE, ifnull/backtick/LOCATE/REGEXP auto-translation, MariaDB-changing tiebreakers).
- Existing disabledLabels and frappe/frappe context are preserved.
